>Magister Scientiae - MSc / Due to the rapid depletion of fossil fuel reserves and the production of environmentally harmful by-products such as carbon dioxide, there is an urgent need for alternate sustainable clean energy. One of the leading candidates in this endeavour is hydrogen, which can be used as an energy carrier since it has a high energy density, zero emissions and is produced from non-depletable resources such as water. The major challenge hindering a hydrogen economy is the lack of safe and effective storage technologies for mobile applications. A prospective solution to this problem lies in the use of porous powdered materials, which adsorb the hydrogen gas. However, the integration of these powdered materials into a storage tank system, results in the pipelines being contaminated during filling cycles. This necessitates the shaping of the porous powdered materials. Among the many shaping techniques available, the electrospinning technique has been proposed as a promising technology since it is a versatile process that is easily scaled-up making it attractive for the applications of the study. Furthermore, the electrospinning process enables the synthesis of nano-sized fibres with attractive hydrogen sorption characteristics. In this regard, the current study employs the electrospinning technique to synthesise electrospun composite fibres for mobile hydrogen storage applications. After electrospinning three polymers, polyacrylonitrile (PAN) was selected as the most suitable polymer because it yielded bead-free electrospun fibres. However, the diameter of the PAN fibres was large/thick which prompted further optimisation of the electrospinning parameters. The optimised electrospinning conditions that yield unbeaded fibres within the desired diameter range (of 300-500 nm) were a PAN concentration of 10 wt%, a flow rate of 0.4 mL/h, a distance of 10 cm between the needle tip and collector plate, and an applied voltage of 8 kV. The study then progressed to the synthesis and characterisation of the pristine porous powdered materials which adsorb hydrogen gas. The porous powdered materials investigated were commercial zeolite 13X, its synthesised templated carbon derivative (ZTC) and Zr (UiO-66) and Cr (MIL-101) based metal-organic frameworks (MOFs). ZTC was synthesised via liquid impregnation coupled with chemical vapour deposition (CVD), and the MOFs were synthesised by the modulated solvothermal method. Analysis of the ZTCs morphology and phase crystallinity show that the carbon templated process using zeolites was successful, however, ZTC was amorphous compared to crystalline zeolite template. The BET surface area was assessed with the aid of nitrogen sorption isotherms for both zeolite 13X and ZTC, and values of 730 and 2717 m²/g, respectively were obtained. The hydrogen adsorption capacity for zeolite 13X was 1.6 wt% and increased to 2.4 wt% in the ZTC material at 77 K and 1 bar. The successful synthesis of well defined, crystalline MOFs was evident from X-ray diffraction and morphological analysis. The BET surface area and hydrogen adsorption for Zr MOF were 1186 m²/g and 1.5 wt%, respectively at 77 K and 1 bar. Cr MOF had a BET surface area of 2618 m²/g and hydrogen adsorption capacity of 1.9 wt% at 77 K and 1 bar. The main focus of the study was to synthesise electrospun composite fibres that can adsorb hydrogen gas and thus provide significant insight in this field of research. As such it examined composite fibres that incorporates porous powdered materials such as zeolite 13X, ZTCs, UiO-66 (Zr) MOF and MIL-101 (Cr) MOF and investigated their ability to adsorb hydrogen gas, which have not been reported previously. The synthesis of composite fibres was achieved by incorporating the porous powdered materials into the PAN resulting in a polymeric blend that was then electrospun. Morphological analysis illustrated that the porous powdered materials were successfully supported by or incorporated within the PAN fibres, forming composite fibres. The BET surface area of the 40 wt% zeolite-PAN and 12.5 wt% ZTC-PAN composite fibres were 440 and 1787 m²/g respectively. Zr MOF and Cr MOF composite fibres had a BET surface area of 815 and 1134 m²/g, respectively. The BET surface area had reduced by 40, 34, 31 and 57% for zeolite 13X, ZTC, Zr MOF and Cr MOF, respectively after these porous powdered materials were incorporated into PAN. The hydrogen adoption capacity for 40 wt% zeolite-PAN, 12.5 wt% ZTC-PAN, 20 wt% Zr MOFPAN and 20 wt% Cr MOF-PAN composite fibres was 0.8, 1.8, 0.9 and 1.1 wt%, respectively. This decrease was attributed to the limited amount of porous powdered materials that could be incorporated into the fibres since only 40 wt% of zeolite 13X, 12.5 wt% of ZTC and 20 wt% of the MOFs were loaded into their respective composite fibres. This was due to the fact that incorporation of greater amounts of porous powdered materials resulted in a viscous polymeric blend that was unable to be electrospun. It is evident from the study that electrospinning is a versatile process that is able to produce composite fibres with promising properties that can potentially advance the research in this field thus providing a practical solution to the problem of integrating loose powdered materials into an on-board hydrogen storage system. / CSIR Young Researchers Establishment Fund (YREF)

Master of Landscape Architecture / Department of Landscape Architecture/Regional & Community Planning / Laurence A. Clement / The Power & Light District is a mixed-use, urban district in the heart of the central business district. The area has seen rapid revitalization since construction began in 2005, and become a popular destination. This project examined the area using a chosen design framework. Documentation and reflection on the application of the design framework was then used to judge its efficacy when applied at the district scale. To gain the desired outcome of this study, there is a two-part research question. 1. How is Kansas City, Missouri’s Power & Light District viewed, and how well does the district score, when using the design framework created in Re-Framing Urban Space: Urban Design for Emerging Hybrid and High-Density Conditions? 2. How well does the Re-Framing Urban Space: Urban Design for Emerging Hybrid and High-Density Conditions design framework work when applied to the Power & Light District in Kansas City, Missouri? This project used several methods to research design frameworks and the Power & Light District. The literature review studies urban design and several design frameworks. GIS diagrams were used to study the Power & Light District. On-site surveys were used to provide public input. Finally, the chosen design framework was used to score the area. Documentation on the use of the design framework was used to reflect on the design framework’s efficacy. Chapter 4 Results and Chapter 5 Conclusions show the application of the design framework to the Power & Light District, and reflections on the efficacy of the framework. The district scores very well with an urban space value of 77%. While the design framework is very extensive, it is meant to judge sites at a smaller scale. For a more accurate scoring of the Power & Light District, the design framework could be adapted to better judge sites at a district scale.

In the medical field images obtained from high definition cameras and other medical imaging systems are an integral part of medical diagnosis. The analysis of these images are usually performed by the physicians who sometimes need to spend long hours reviewing the images before they are able to come up with a diagnosis and then decide on the course of action. In this dissertation we present a framework for a computer-aided analysis of medical imagery via the use of an expert system. While this problem has been discussed before, we will consider a system based on mobile devices. Since the release of the iPhone on April 2003, the popularity of mobile devices has increased rapidly and our lives have become more reliant on them. This popularity and the ease of development of mobile applications has now made it possible to perform on these devices many of the image analyses that previously required a personal computer. All of this has opened the door to a whole new set of possibilities and freed the physicians from their reliance on their desktop machines. The approach proposed in this dissertation aims to capitalize on these new found opportunities by providing a framework for analysis of medical images that physicians can utilize from their mobile devices thus remove their reliance on desktop computers. We also provide an expert system to aid in the analysis and advice on the selection of medical procedure. Finally, we also allow for other mobile applications to be developed by providing a generic mobile application development framework that allows for access of other applications into the mobile domain. In this dissertation we outline our work leading towards development of the proposed methodology and the remaining work needed to find a solution to the problem. In order to make this difficult problem tractable, we divide the problem into three parts: the development user interface modeling language and tooling, the creation of a game development modeling language and tooling, and the development of a generic mobile application framework. In order to make this problem more manageable, we will narrow down the initial scope to the hair transplant, and glaucoma domains.

The Sustainable Development Goals (SDGs) express the commitment of countries to integrate ecosystem and biodiversity values into national planning. The System of Environmental-Economic Accounting – Experimental Ecosystem Accounting (SEEA-EEA) is an emerging international standard measurement framework for national ecosystem accounting. The international official statistics community proposes the SEEA-EEA as a means of integrating ecosystem and biodiversity values into national planning by providing guidance on measuring ecosystems and their contribution to the economy. Implementation of such a common measurement framework requires agreement among diverse ethical perspectives, disciplines, national contexts and roles on what to measure, how to measure it and how to interpret those measures to support a common policy direction. This thesis asks the question: If the aim is to provide guidance to countries on integrating ecosystem and biodiversity values into national planning, how could one foster convergence on a common national ecosystem accounting framework that is sufficiently comprehensive to capture the important linkages between ecosystems and human well-being, sufficiently convergent to be accepted by diverse perspectives, sufficiently rigorous for national official statistics, sufficiently consistent to allow for time-series and international comparisons and sufficiently feasible to be affordable for national governments to implement and maintain? To address this broader question, this thesis investigates the sources of divergence in national ecosystem accounting and develops tools to assess and to foster convergence. To accomplish this, I focussed on the following four research questions in four separate papers: 1. How should we think about ecosystem measurement if the aim is comprehensiveness, practicality, and convergence? [Chapter 2] This ethical analysis concludes that for ecosystem accounting to be universal, it needs to explicitly and simultaneously address broad human values, long time-frames, and the concepts of Critical Natural Capital and precaution. 2. What approaches to ecosystem accounting have already been developed and are they sufficient? [Chapter 3] This review of 16 state-of-the-art frameworks finds that none addresses all requirements for convergence on a common national ecosystem accounting framework. Collectively, they provide insufficient guidance on ecosystem classification, measurement in general, delineating Critical Natural Capital, incorporating broad human values and measuring statistical uncertainty. 3. Where is the divergence of values and preferences within the broader community of practice (researchers, users, analysts)? [Chapter 4] This cluster analysis of a survey of 131 expert stakeholders in national ecosystem accounting revealed agreement on the need for broadening the scope, addressing multiple decision contexts and furthering the development of national ecosystem accounting. The most important divergence issues in this community of practice were attributed to different ethical perspectives and differences in interpretation of core concepts. 4. Are current classifications of ecosystems and ecosystem services sufficient for national ecosystem accounting? [Chapter 5] This meta-analysis integrates nine comprehensive ecosystem assessments. It concludes that the lack of rigour in current classifications impedes consensus on aggregating information on “Which ecosystems produce which services?” and therefore current approaches are insufficient for national ecosystem accounting. I suggest an improved ecosystem classification for future studies. In the concluding chapter, I present a synthesis of research arguments and findings of the previous four chapters. The main outcome of this research has been not only the specific findings of the individual chapters, but also the development of a normative and empirically-supported toolkit to improve convergence and aggregation in future national ecosystem accounting frameworks: - Four normative criteria to assess frameworks and to incorporate into future designs and revisions, - A critical comparative assessment of current frameworks, - An empirically supported analysis of the preferences of the community of practice, and - A systematic approach for determining priority ecosystems and services for national ecosystem accounting. This thesis concludes that national ecosystem accounting can be a valuable tool for national planning. The approaches suggested can be applied to establishing a constructive national dialogue on national environmental priorities, to provide evidence to inform those priorities and to apply this evidence to support common policy platforms. However, care must be taken in its implementation to minimize the inherent risks of oversimplification and homogenization of the diverse stakeholder and scientific perspectives.

In this thesis, we aim to investigate the thermoresponsive behaviour, especially negative thermal expansion (NTE), in metal dicarboxylate metal organic frameworks (MOFs) using X-ray diffraction techniques. Four materials with the UiO-66 topology [Zr6O4(OH)4(bdc)12], [Zr6O6(bdc)12], [Zr6O6(bpdc)12] and [Zr6O6(2,6-ndc)12] (bdc = 1,4-benzenedicarboxylate, bpdc = 4,4’-biphenyldicarboxylate and 2,6-ndc = 2,6-napthalenedicarboxylate) were investigated, all of which contain a zero-dimensional inorganic cluster. All four members show NTE behaviour over the observed temperature ranges as a result of the twisting motion of the carboxylate groups of the organic linkers. This twisting motion introduces a concerted rocking motion within the inorganic cluster which causes an apparent decrease in the size of the cluster and hence overall volume contraction. Alteration of the structure of the organic linker has an effect on the magnitude of the expansivity coefficient which is believed to be related to the existence of specific vibrational modes of that particular organic linker. Four members of the MIL-53 family [Al(OH)(bdc)], [AlF(bdc)], [Cr(OH)(bdc)] and [VO(bdc)] were studied. All four materials show elements of NTE behaviour related to a “wine rack” thermo-mechanical mechanism which is determined by the connectivity of the framework. The thermoresponsive behaviour in these materials is dominated by the changes in the plane of the pore opening. These changes result from a combination of three distinct types of motion of the bdc linker including the rotation of the bdc linker about the chain of the inorganic octahedra, the “knee cap” bending mode of the carboxylate groups about the O-O vector and possibly the transverse vibrations within the bdc linker. The latter motion was not evident in this work due to the limitations of the structure refinements. The former two motions appear to be correlated and depend on the rigidity of the metal-centred octahedra which is determined by the constituent metal cation and anion types. The rigidity of the octahedra is also found to play an important role in determining whether the material undergoes a “breathing” phase transition at low temperature. [Sc2(bdc)3] shows NTE behaviour over the observed temperature range which is partially driven by a “wine rack” thermo-mechanical mechanism, but with an opposite framework compression direction when compared to the MIL-53 types MOFs. This is due to the presence of an additional bdc connecting linker in the plane of the pore opening. This extra connection inverses the compression direction and also impedes the structural changes in the plane of the pore opening. The contraction of the chain of inorganic octahedra is the main contributor to the overall unit cell contraction and is caused by the twisting motion of the carboxylate groups of the bdc linker while the magnitude of this contraction is determined by the flexibility of the chain of inorganic octahedra.

The Internet today has a phenomenal reach---right into the homes of a vast audience worldwide. Some organisations (and individuals) see this medium as a good opportunity for extending the reach of their computer systems. One popular approach used for such endeavours is to run an application on a server, using web technology for displaying its user interface (UI) remotely. Developing such a web-based UI can be quite tedious---it is a concurrent, distributed program which has to run in a hostile environment. Furthermore, the platform on which it is implemented (the web) was not originally intended for such usage. A web framework is a collection of software components which provides its users with support for developing and executing web-based UIs. In part, web frameworks can be seen as being analogous to interpreters: given a specification of a UI using a specification technique dictated by the framework, server components of the framework can present the UI using web technology. Topics related to web frameworks are scarce in the academic literature, but abound in industry and open discussion forums. Similarly, the designers of web frameworks seldom found their work on existing theory in the literature. This study is an attempt to bridge this gap. It is focused on two aspects of web frameworks: the specification technique a framework mandates, and how such a specification can subsequently be used to present a UI via web technology. As part of this study, a survey was conducted of 80 open source web frameworks. Based on the survey, a partial overview of the domain of web frameworks is given, covering what is seen as being typically required of a web framework and covering specification techniques that are used by existing frameworks. Two taxonomies are proposed of the strategies web frameworks use for specifying two aspects of web UIs. Using the web as platform implies adherence to certain (intended) architectural constraints. Web framework designers often strain against these constraints. However, another point of view is to recognise that the success of the web platform is made possible precisely because of its intended architecture. (And the success of the web is surely the principal motivation for using it for remote UIs in the first place.) With the bias of this viewpoint, a specification technique is proposed for web-based UIs. This technique is based on the well-known formalism of statecharts, with semantics explicitly defined in terms of the intended architectural components and constraints of the web. The design of a web framework for presenting a UI so specified is also proposed (based on the theoretical background given, as well as two prototype implementations which have been developed). / Dissertation (MSc)--University of Pretoria, 2007. / Computer Science / unrestricted

A significant and ongoing challenge in materials chemistry and furthermore solid state chemistry is to design materials with the desired properties and characteristics. The field of Metal-Organic Frameworks (MOFs) offers several strategies to address this challenge and has proven fruitful at allowing some degree of control over the resultant materials synthesized. Several methodologies for synthesis of MOFs have been developed which rely on use of predetermined building blocks. The work presented herein is focused on the utilization of two of these design principles, namely the use of molecular building blocks (MBBs) and supermolecular building blocks (SBBs) to target MOF materials having desired connectivities (topologies). These design strategies also permit the introduction of specific chemical moieties, allowing for modification of the MOFs properties. This research is predominantly focused on two platforms (rht-MOFs and ftw-MOFs) which topologically speaking are edge transitive binodal nets; ftw being a (4,12)-connected net and rht being a (3,24)-connected net. These highly connected nets (at least one node having connectivity greater than eight) have been purposefully targeted to increase the predictability of structural outcome. A general trend in topology is that there is an inverse relationship between the connectivity of the node(s) and the number of topological outcomes. Therefore the key to this research (and to effective use of the SBB and MBB approaches) is identification of conditions which allow for reliable formation of the targeted MBBs and SBBs. In the case of the research presented herein: a 12-connected Group IV or Rare Earth based hexanuclear MBB and a 24-connected transition metal based SBB were successfully targeted and synthesized. These two synthetic platforms will be presented and used as examples of how these design methods have been (and can be further) utilized to modify existing materials or develop new materials for gas storage and separation applications for environmental and energy related applications including hydrogen, methane, carbon dioxide and hydrocarbon storage or separations.

Thesis advisor: Chia-Kuang Tsung / Heterogeneous catalysis is a critical field for chemical industry processes, energy applications, and transportation, to name a few. In all avenues, control over the activity and selectivity towards specific products are of extreme importance. Generally, two separate methods can be utilized for controlling the active surface areas; a below and above the surface approach. In this dissertation, both approaches will be addressed, first starting with controlling the active sites from a below approach and moving towards control through sieving and gating effects above the surface. For the first part half, the control of the product selectivity is controlled by finely tuning the atomic structures of nanoparticle catalysts, mainly Au-Pd, Pd-Ni-Pt, and Pd Ni3Pt octahedral and cubic nanoparticle catalysts. Through these shaped core-shell, occasionally referred to as core@shell, particles the shape is maintained in order to expose and study certain crystal facets in order to obtain a more open or closed series of active sites. With the core shell particles, the interior core particle (Au and Pd) is used for the overall shape but also to expansively/compressively strain the outer shell layer. By straining the surface, the surface electronic structure is altered, by raising or lowering the d-band structure, allowing for reactants to adsorb more or less strongly as well as adsorb on different surface sites. For the below the surface projects, the synthesized nanoparticle catalyst are used for electrochemical oxidation reactions, such as ethanol and methanol oxidation, in order to study the effect of the core and shell layers on initial activity, metal migration during cycling, as well as particle stability and activity using different crystal structures. In particular, the use of core shell, alloyed, and intermetallic (ordered alloys) particles are studied in more detail. In the second half of this dissertation, control of the selectivity will be explored from the top down approach; in particular the use of metal organic framework (MOF) will be utilized. MOF, with its inherent size selective properties due to caging effects from the chosen linkers and nodes, is used to coat the surface of catalysts for gas, liquid, and electrochemical catalysis. By using nanoparticle catalyst, the use of MOF, more explicitly the robust zirconium based UiO-66, as a crystalline capping agent is first explored. By incorporating both the nanoparticle and UiO-66 amino functionalized precursors in the synthesis, the nanoparticles are formed first and followed by coating in UiO-66-NH2, where the amino group acts as an anchor, completely coating the particles. The full coating is tested through size selective alkene hydrogenations with the NP surface further tested by liquid phase selective aldehyde hydrogenations; the UiO-66-NH2 pores help to guide the reactant molecule in a particular orientation for the carbonyl to interact rather than the unsaturated C=C bond. This approach is taken for more complex hybrid structures for electrochemical proton exchange membrane fuel cell (PEMFC) conditions. Through the gating effects, the UiO-66 blocks the Pt surface active sites from poisonous sulfonate groups off of the ionomer membrane while simultaneously preventing aggregation and leaching of Pt atoms during electrochemical working conditions. / Thesis (PhD) — Boston College, 2018. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.